Electromagnetic load relay having an insulated barrier between contacts



A ril 1, 1969 R. R. SNYDER 3,436,697

ELECTROMAGNETIC LOAD RELAY HAVING AN INSULATED BARRIER BETWEEN CONTACTS Filed Sept. 21, 1966 Sheet of 5 4e A i; /G

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, ATTORNEYS A ril 1, 1969 R. R. SNYDER 3,436,697

ELECTROMAGNETIC LOAD RELAY HAVING AN INSULATED BARRIER BETWEEN CONTACTS Filed Sept. 21, 1966 Sheet 2 of 3 B RosEiT-R swasz F I G. 3

BY Meqafldmm; 8 80:14,

AT TORN EYS April l, 1969 R R. SNYDR 336 ELECTROMAGNETIC LbAD RELAY HAVING AN INSULATED BARRIER BETWEEN CONTACTS Filed Sept. 21, 1966 Sheet 3 of 3 FIG. 4

. INVENTOR. ROBERT R. SNYDER BY Mm, WM, 1: and,

ATTORNEYS United States Patent 3 436,697 ELECTROMAGNETIC LOAD RELAY HAVING AN INSULATED BARRIER BETWEEN CONTACTS Robert Raymond Snyder, Molina, IlL, assignor to E. W. Bliss Company, Canton, Ohio, a corporation of Delaware Filed Sept. 21, 1966, Ser. No. 581,070 Int. Cl. H0111 37/02, 15/02 U.S. Cl. 335-115 13 Claims ABSTRACT OF THE DISCLOSURE An electromagnetic load relay having a barrier located between the pairs of contacts, which serves to carry as well as electrically insulate the contact assemblies.

This invention relates to the art of relays and, more particularly, to an improved relay construction.

The invention is particularly applicable as a load relay for switching high values of current, such as fifteen amperes, across a load and will be described with particular reference thereto; although, it is to be appreciated that the invention has broader applications and may, for example, be used in conjunction with switching low values of current across a load.

Electromagnetic relays known heretofore have included both clapper type relays and solenoid type relays. In either type, the stationary contacts are normally connected to terminals, such as plug-in terminals, by means of relatively thin, easily breakable conductor wires. Such wires must be soldered both to the relay stationary contacts and the plug-in terminals.

Where a relay includes multiple contact assemblies, insulator barriers are normally positioned between the assemblies to prevent short circuits therebetween. These barriers normally serve no other purpose and separate mounting facilities are provided for mounting the required contact circuit assemblies.

The present invention is directed toward an improved relay construction having a common mounting barrier which serves to carry, as well as electrically insulate, a pair of contact circuit assemblies, thereby overcoming the noted disadvantages, as well as others, of previous relays.

In accordance with one aspect of the present invention, the relay includes first and second contact circuit assemblies, each including at least one stationary contact and one movable contact; means, such 'as a solenoid, for displacing the movable contact relative to the stationary contact; and, a common insulator mounting barrier electrically separating the first and second assemblies and carrying the stationary contacts of the assemblies.

In accordance with a still further aspect of the present invention, each stationary contact is electrically connected to a rigid, conductive contact bracket which is secured to one side of the barrier.

:In accordance with a still further aspect of the present invention, the barrier extends from an insulator base and each contact bracket extends through the base so that the extended through bracket portions define plugin terminals adapted for plug-in mounting in an electrical receptacle.

In accordance with a still further aspect of the invention, the movable contact displacing means includes a solenoid having a movable core member having an axis of movement extending transversely of the barrier.

The primary object of the present invention is to provide an improved relay of simple and rugged construction, and which is economical to manufacture.

Another object of the present invention is to provide ICC a relay which maintains reliability of operation for a long operating lifetime.

A still further object of the present invention is to provide an improved relay wherein the contact pressure is relatively uniform throughout the entire limits of travel.

A still further object of the present invention is to provide an improved relay which is easily and rapidly assembled from parts that can be mass produced from moldings or stampings, requiring no machining.

A still further object of the present invention is to provide an improved relay construction so that each of its separate component parts has means for precisely registering with another to provide a compact unitary structure which does not require any post assembly adjustments.

A still further object of the present invention is to provide an improved relay having combined terminal pins and contact circuit bus members having no intermediate points, thereby eliminating possible hot spots.

A still further object of the present invention is to provide an improved relay wherein the movable contacts have sufficient over-travel so as to eliminate or reduce contact bounce, essential to long contact life.

A still further object of the present invention is to provide an improved relay particularly adapted for use with tungsten lamp loads having a high in-rush current.

These and other objects and advantages of the invention will become apparent from the following description of the preferred embodiment of the invention as read in connection with the accompanying drawings in which:

FIGURE 1 is a schematic illustration of the preferred embodiment of the relay;

FIGURE 2 is an elevational view of the details of construction of the preferred embodiment of the relay;

FIGURE 3 is a plan view partly in section of the embodiment illustrated in FIGURE 2;

FIGURE 4 is a sectional view taken line 4-4, looking in the direction of the arrows, in FIGURE 2;

FIGURE 5 is a sectional view taken along line 5--5, looking in the direction of the arrows, in FIGURE 4;

FIGURE 6 is a sectional view taken along the line 6--6, looking in the direction of the arrows, in FIG- URE 5;

FIGURE 7 is a partial view illustrating one aspect of the operation of the relay; and,

FIGURE 8 is a partial view similar to that as in FIGURE 7 illustrating another aspect of the operation of the relay.

Referring now to the drawings and, more particularly, to FIGURES 1 through 4, there is illustrated a preferred embodiment of the relay which generally comprises an electromagnetic acuator E, a contact lifter assembly F, a right hand contact circuit assembly G, a left hand contact circuit assembly H, a common mounting barrier I, a base J, and a frame yoke K.

Contact circuit assemblies Contact circuit assemblies G and H each have a contact pole arrangement known as single pole-double thr0wdouble break (SP-DT-DB). Thus, the two assemblies taken together have a contact pole arrangement known as double pole-double throw-double break (DP-DT-DB). The two assemblies are substantially identical and, accordingly, only the right hand assembly G will be de scribed in detail hereinafter, like components in both assemblies being identified with like reference characters where appropriate. As shown in FIGURES 2, 4, 7 and 8, assembly G includes a pair of spaced upper stationary contacts 10 and 12, a pair of correspondingly spaced lower stationary contacts 14 and 16. Interposed between the upper and lower stationary contacts there is provided an upper contact bar 18 and a lower contact bar 20. Contact bar 18 carries movable contacts 22 and 24 adapted for engagement with upper stationary contacts 10 and 12, respectively. Similarly, lower contact bar 20 carries movable cont-acts 26 and 28 adapted for engagement with lower stationary contacts 14 and 16, respectively. Contact bars 18 and 20 are resiliently biased in opposing directions by means of a coil spring 30 interposed between the two bars and held in place by means of posts 32 and 34 respectively extending from bars 18 and 20.

Preferably, contact bars 18 and 20 are constructed of copper and the moveable contacts are secured, as by bonding, to the contact bars with a silver interlay 36 interposed between the contact and the bar. The silver interlay is preferably of a thickness on the order of 20% of the total contact height X (see FIGURE 8), which is preferably on the order of 0.04 inch.

Upper and lower stationary contacts 10 and 14 are respectively secured, as by bonding, to contact leg portions 38 and 40 of contact bracket B, with each contact preferably having a silver interlay 42 between the contact and the respective legs of bracket B. Similarly, upper and lower stationary contacts 12 and 16 are secured, as by bonding, together with a silver interlay 42, to contact portions 44 and 46 of contact brackets C and A, respectively. The total height Y (see FIGURE 7) of each stationary contact (including the silver interlay 42) is preferably on the order of 0.04 inch.

Contact brackets and mounting barrier Contact brackets A, B and C are constructed of rigid, conductive material, such as brass, and extend parallel to each other from the stationary contacts at contact circuit assembly G and through insulator base J, with the extended through portions of the brackets defining plug-in prongs 46, 48 and 50, respectively. These prongs are sufiiciently rigid that they are adapted for mounting at a conventional plug-in type electrical socket. Immediately below prong 50 in FIGURE 2 there is provided an additional prong 52 which is the extended through portion of a bracket D, which is also constructed of rigid conductive material, such as brass, but which is used to cnnect the coil of the electromagnetic actuator E with a source of power.

As shown in FIGURES 2 and 3, the common mounting barrier I, which is preferably constructed of insulation material, is mechanically secured to and extends from the top portion of insulator base J in such a manner that the barrier extends parallel to contact brackets A, B and C. If desired, barrier I and base I may be a unitary structure, with barrier I extending in cantilevered fashion from base J. Flat elongated bracket insulators 54 and 56 serve to electrically insulate brackets A, B and C from each other. This laminated assembly of brackets A, B and C and insulators '54 and 56 are sandwiched together and secured to the common mounting barrier I by means of suitable nut and bolt arrangements 58, which extend transversely through the laminated assemblies located on both the right and left hand sides of barrier I. Preferably, the bolt portions of these arrangements extend through insulated sleeves 60. In addition, suitable clamp plates 62 and insulator barrier 64, between the clamp plates and brackets B, are provided for both the left and right hand sides of the barrier.

Electromagnetic actuator The electromagnetic actuator, as best shown in FIG- URES 2 and 4, takes the form of a solenoid including a U-shaped frame 66, constructed of suitable magnetic material, having a base 68 and upwardly extending legs 70 and 72. A frame head 74, of suitable magnetic material, is secured to legs 70 and 72. Suitably mounted within frame 66 there is provided a coil bobbin 76 constructed of insulation material. Bobbin 76 includes a cylindrical sleeve 78 having one end thereof extending through a suitable aperture 80 in frame head 74. Upper and lower flanges 82 and 84 extend radially outward from sleeve 78 and serve to contain the solenoid coil 86. The solenoids movable core 88, which takes the form of a cylindrical plunger, is located coaxially within sleeve 78 of bobbin 76 for reciprocal movement along an axis aligned substantially perpendicularly of the common mounting barrier 1. Immediately below core 88, there is illustrated in FIGURE 4 a core head having a shank portion 92 extending through an aperture 94 in frame base 68, and suitably secured thereto, as by staking. Core head 90 includes an upper extended cylindrical shank portion 96, the upper surface 98 thereof serving as a lower stop for the movement of core 88. As shown in FIGURES 5 and 6, core head 90 includes an annular recess 100 in its upper surface for receiving a shading ring 102 when used for AC. operation. Shading ring 102 is preferably secured to core head 90 as by staking, as shown in FIG- URE 5. It will be noted that the upper surface 104 of the core head portion, which coaxially surrounds the central elevated portion 96, is lower than surface 98 by preferably a distance on the order of 0.006 inch. This arrangement provides a double pole at the face of the core head, and by virtue of the shading ring places two poles magnetically out of phase by 180 for sealing the movable core face to the pole face of the core head and eliminating A.C. chatter or hum.

Contact I i fter assembly The contact lifter assembly F includes a U-shaped contact lifter 110, of insulation material, having a base 112 and two upwardly extending legs 114 and 116. Base overlies and bisects core 88, and is secured thereto by means of a suitable screw 118. A washer is interposed between the upper surface of core 88 and a recess 122 in the lower surface of base 112. The outer diameter of washer 120 is slightly less than the diameter of recess 122 so as to define an annular groove 124. Groove 124 serves to receive the top end of a coil type return spring 126, which coaxially surrounds the outer surface of sleeve 78, with the lower end of the spring being seated on the upper surface of frame head 74. Thus, it is appreciated that the groove 124 serves to center the return spring 126.

Each of the upstanding legs 114 and 116 of contact lifter 110 includes a rectangular shaped aperture, hereinafter referred to as window 128. These windows serve to receive the upper and lower movable contacts which are held in place by means of upwardly extending retainer walls 130, suitably secured to upstanding legs 114 and 116.

As shown in FIGURES 7 and 8, the upper and lower movable contacts of the right hand contact circuit assembly G are retained in window 128 in leg 114 of contact lifter 110. Vertical movement of the moveable contacts within window 128 is limited by an upper window surface 134 and a lower window surface 136.

Frame yoke The frame yoke K, as illustrated in FIGURES 2, 3 and 4, takes the form of a U-shaped member having two legs and 142 extending substantially parallel to each other, and interconnected by an intermediate portion or base 144. Legs 140 and 142 are each secured at their free end to insulator base I by means of suitable screws 146, and extend away from base I so as to enclose contact circuit assemblies G and H, the contact lifter assembly F and the electromagnetic actuator E. The base 68 of the solenoid frame 66 rests on leg 140 with a magnetic insulator sheet 148 interposed therebetween, and is suitably secured to leg 140 by screws 150. An insulator sheet 152 is interposed between upper leg 142 of yoke K and the common mounting barrier I. Insulator sheet 152 is preferably of a width corresponding substantially with that of leg 142 and extends from insulator base I a suflicient distance to overlay the right and left hand contact circuit assemblies G and H. In additon, a pair of apertures 154 and 156 are provided which extend through leg 142 and insulator sheet 152 directly over and in registry with upstanding legs 114 and 116, respectively, of contact lifter 110. Legs 114 and 116, respectively, include extended portions 158 and 160, which upon deenergization of coil 86 extend upwardly through apertures 154 and 156, respectively. Portions 158 and 160 serve as a safe means to permit manual actuation of the relay contacts.

Operation In the nonoperative condition, the contact lifter 110 is disposed at its upper extremity of movement, limited by the lower edge of the common mounting barrier I. The lifter 110 is maintained in this position by the bias provided by return spring 126. The upper movable contacts 22 and 24 are thus resiliently maintained in engagement with upper stationary contacts and 12, respectively, by means of spring 32 interposed between contact bars 18 and 20. Thus, an electric circuit is completed between the upper stationary contacts through contact bar 18. This condition of the relay may be termed as the normally closed condition.

Upon energization of coil 86, movable core 88 is attracted to core head 90, whereupon core 88 is displaced in a downward direction as indicated by the arrow in FIGURE 8. Accordingly, the upper window surface 134 of lifter 110 strikes the top surface of upper contact bar 18 so as to positively break electrical contact betweenthe upper movable contacts and the upper stationary contacts. During the downward travel of the movable contacts, coil spring 30 tends to bias the upper contact bar 18 and the lower contact bar 20 in opposing directions against window surfaces 134 and 136, respectively. Before core 88 completes its downward travel, and is magnetically sealed to core head 90, the lower movable contacts 26 and 28 engage the lower stationary contacts 14 and 16, respectively, thereby completing an electrical circuit between the lower stationary contacts. Core 88 and, hence, lifter 110 continue their downward movement until the core is magnetically sealed to core head 90. This overtravel is resisted by spring 30, with the extent of overtravel S (see FIGURE 8) as measured from the lower contact bar 20 to the window surface 136- being preferably equal to the contact height X which, as stated hereinbefore, is preferably on the order of 0.040 inch. Similarly, upon de-energization of coil 86, the contact lifter 110 is driven in an upward direction, as indicated by the arrow in FIGURE 7, by forces imparted by return spring 126. As lifter 110 moves in an upward direction, the lower window surface 136 strikes lower contact bar 20 so as to positively break electrical engagement be tween the lower movable contacts and the lower stationary contacts. Before lifter 110 reaches its upper extremity of movement, the upper movable contacts 22 and 24 engage stationary contacts 10 and 12, respectively, thereby completing a circuit between the upper stationary contacts. Lifter 110 then completes its upward movement, limited by the lower edge of the common mounting barrier I with the resulting overtravel S (see FIGURE 7) being preferably on the order of 0.040 inch.

Although the invention has been shown in connection with a preferred embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention as defined by the appended claims.

Having thus described my invention, I claim:

1. An electromagnetic relay comprising:

first and second contact circuit assemblies, each including at least one stationary contact and one movable contact;

means for displacing said movable contact with respect to said stationary contact;

a stationary common insulator mounting barrier completely separating said first and said second assemblies, said stationary contact of each said contact assembly being electrically connected to a conductive contact bracket, said contact brackets of said first and said second assemblies being located on and secured to opposite sides of said stationary barrier and orientated in superimposed parallel relationship with said barrier; and,

means for securing said contact brackets and barrier together in laminated fashion.

2. An electromagnetic relay as set forth in claim 1, including an insulator base, each said contact bracket extending through said base so that the extended through bracket portions define plug-in terminals adapted for plug-in mounting in an electrical receptacle.

3. An electromagnetic relay comprising:

first and second contact circuit assemblies, each including at least one stationary contact and one movable contact;

means for displacing said movable contact with respect to said stationary contact;

a stationary common insulator mounting barrier electrically separating said first and second assemblies;

said stationary contact of each said assembly being electrically connected with a rigid contact bracket of conductive material, said contact brackets of said first and said second assemblies being located on and secured to opposite sides of said stationary barrier and orientated in superimposed parallel relationship with said barrier;

said relay further including an insulator base, each said contact bracket extending through said base so that the extended through bracket portions define plug-in terminals adapted for plug-in mounting in an electrical receptacle; and

each said assembly includes at least a second stationary contact secured to a second said contact bracket, the contact brackets on each side of said barrier member being separated from each other by insulation and secured to a respective one side of said barrier in laminated fashion.

4. An electromagnetic relay as set forth in claim 3, wherein said movable contact displacing means includes a solenoid having a movable core coupled with said movable contacts.

5. An electromagnetic relay as set forth in claim 4, wherein each said contact circuit assembly includes at least two stationary contacts and two movable contacts mounted on a conductive bridge member, said movable core coupled to said bridge member for displacing both said movable contacts into concurrent engagement with said two stationary contacts.

6. An electromagnetic relay as set forth in claim 5, including resilient means interposed between said core member and said bridge member permitting overtravel of said core member as it displaces said movable contacts into engagement with said stationary contacts.

7. An electromagnetic relay as set forth in claim 5, wherein each said contact assembly includes two additional stationary contacts facing said other two stationary contacts, and two additional movable contacts mounted on a second conductive bridge member for engagement with said two additional stationary contacts.

8. An electromagnetic relay as set forth in claim 7, including a contact lifter member directly connected to said core member and having two Window apertures, each for carrying said first and second bridge members of one of said contact circuit assemblies.

9. An electromagnetic relay as set forth in claim 8, including resilient means interposed between said first and second bridge members.

10. An electromagnetic relay as set forth in claim 4,

wherein said barrier extends transversely of the axis of movement of said solenoid core member.

11. An electromagnetic relay as set forth in claim 4, wherein said barrier extends substantially perpendicularly of said axis and overlies said solenoid in such a manner as to substantially bisect said solenoid.

12. An electromagnetic relay as set forth in claim 10, including a U-shaped frame having two leg members and a leg interconnecting member, said solenoid being secured to one of said leg members, the ends of said leg members being secured to opposing sides of said insulator base in such a manner that said leg interconnecting member is spaced from and extends substantially parallel to said insulator base.

13. An electromagnetic relay as set forth in claim 1, wherein said contact brackets are of a generally thin cross-sectional configuration, and said brackets are laminated on opposite sides of said barrier.

References Cited UNITED STATES PATENTS 10 BERNARD A. GILHEANY, Primary Examiner.

D. M. MORGAN, Assistant Examiner.

US. Cl. X.R. 

